Another example of unfinished studies and preparation for our annual event of HAZE from Indonesia. What size of particles, what kind of danger and how to prevent from enter human body and cause death.

According to U.S. Environmental Protection Agency (EPA), particles less than 10 micrometers are dangerous when inhaled and accumulated in the respiratory system. Due to their small size, these particles can “lodge deeply into the lungs”.

Public ask information on PM2.5 instead of PM10 alone. prolonged exposure to the poor air quality, which has plunged to hazardous levels in recent days. In particular,  levels of PM2.5 concentration, or very fine particulate matter.
             
For example, the PM2.5 concentration went up to about 304 μg/m3 at 4pm yesterday, way past its normal levels of between 20 and 40 μg/m3 in Singapore. The PM2.5 concentration reading measures small particles of less than 2.5 microns in diameter, which can slip past the nasal passages into the lungs and blood streams, potentially creating an entire host of problems from heart attacks to stroke and even brain damage in extreme cases.

In comparison, the PM10 concentration reading tracks particles that are less than 10 microns in diameter, which get trapped in the nasal passage. Nevertheless, the doctors stressed that the severity of conditions depends on the amount of pollutants breathed in by a person, so the exposure during normal commuting would not be considered too hazardous.

The much smaller PM2.5 particles can go anywhere in the body, any organs. This can trigger inflammation of the blood vessels and lead to heart attacks, even in people with no history of heart disease. The inflammation could occur in unborn fetuses and these children have a higher risk of developing asthma after they are born.

One of the effects could even be brain damage, occurring at a similar level to people with Alzheimer’s disease. But the effect is dose dependent. How long people need to be breathing in the polluted air to suffer such hazardous effects is not known.

For average office workers, the PSI levels of beyond 300 do not pose a threat so severe that they have to stop working or work from home. But for people who work outside, such as delivery drivers, it is hazardous, as they work outside all day long. Their number of working hours should be limited and they must be made to wear N95 masks.

60 per cent of the haze particles may penetrate indoors, depending on air flow, and using air-conditioning and closing windows and doors may bring down the level.